BACKGROUNDHuman herpesvirus 8 (HHV8), the infectious cause of Kaposi sarcoma, varies dramatically across Africa, suggesting that cofactors correlated with large-area geographic or environmental characteristics may influence risk of infection. Variation in HHV8 seropositivity across small-area regions within countries in Africa is unknown. We investigated this issue in Uganda, where Kaposi sarcoma distribution is uneven and well described.METHODSArchival samples from individuals aged 15-59 years randomly selected from a nationally representative 2004-2005 human immunodeficiency virus-AIDS serobehavioral survey were tested for HHV8 seropositivity with use of enzyme immunoassays based on synthetic peptides from the K8.1 and orf65 viral genes. Adjusted odds ratios and 95% confidence intervals (CIs) of association of HHV8 seropositivity with demographic risk factors were estimated.RESULTSAmong 2681 individuals tested, HHV8 seropositivity was 55.4%. HHV8 seropositivity was lower in female than in male persons (adjusted odds ratio, 0.82 [95% CI, 0.69-0.97]) and increased 2.2% (95% CI, 1.0%-3.6%) in female persons and 1.2% (95% CI, 1.0%-2.3%) in male persons per year of age. HHV8 seropositivity was inversely associated with education ( P = .01, for trend) and was elevated in the West Nile region, compared with the Central region (adjusted odds ratio, 1.49 [95% CI, 1.02-2.18]) but not with other regions.CONCLUSIONSOur findings suggest that HHV8 seropositivity in Uganda may be influenced by cofactors correlated with small-area geography, age, sex, and education.